Bi-directional power electronics circuit for electromechanical valve actuator of an internal combustion engine

Abstract

A bi-directional dual coil half bridge converter adapted to be coupled to a dual coil actuator of a cylinder valve in an internal combustion engine is described. In one example, the converter has a first and second capacitor and a voltage source, where the converter is actuated via switches to individually energizing coils in said dual coil actuator. A voltage regulator is also shown for maintaining midpoint voltage during unequal loading of different actuator coils in the converter.

1. An electronic circuit, comprising:
 a first electromechanical actuator coil coupled to one of a plurality of cylinder valves of an internal combustion engine, where a first end of said first electromechanical actuator coil is coupled to a reference; 
 a second electromechanical actuator coil, where a first end of said second electromechanical actuator coil is coupled to said reference; 
 a first energy storage device, where a first end of said first energy storage device is coupled to said reference; 
 a second energy storage device, where a first end of said second energy storage device is coupled to said reference; 
 a first switch, where a first end of said first switch is coupled to a second end of said first electromechanical actuator coil; 
 a second switch, where a first end of said second switch is coupled to said second end of said first electromechanical actuator coil; 
 a third switch, where a first end of said third switch is coupled to a second end of said second coil; 
 a fourth switch, where a first end of said fourth switch is coupled to said second end of said second coil; and 
 a controller to activate said switches to route electrical energy from at least one of said energy storage devices through each of said first and second coils in any one of two opposing directions. 
 
     
     
       2. The circuit of  claim 1  wherein a second end of said first switch is coupled to a second end of said first energy storage device. 
     
     
       3. The circuit of  claim 1  wherein a second end of said second switch is coupled to a second of said second energy storage device. 
     
     
       4. The electronic circuit of  claim 1  wherein said second electromechanical actuator coil is coupled to one of said plurality of valves, and one of said first and second electromechanical actuator coil positioned in an actuator having a permanent magnet. 
     
     
       5. The electronic circuit of  claim 4  further comprising a third electromechanical actuator coil, where a first end of said third electromechanical actuator coil is coupled to said reference. 
     
     
       6. The electronic circuit of  claim 1  wherein said first energy storage device is a first capacitor. 
     
     
       7. The electronic circuit of  claim 6  wherein said second energy storage device is a second capacitor. 
     
     
       8. The electronic circuit of  claim 1  further comprising:
 a voltage source, with a first end of said source coupled to a second end of said first energy storage device. 
 
     
     
       9. The electronic circuit of  claim 8  wherein a second end of said source is coupled to a second end of said second energy storage device. 
     
     
       10. A system, comprising:
 a bi-directional converter adapted to be coupled to a plurality of single or multiple coil actuators having a permanent magnet, said actuators coupled to valves of a cylinder, where a plurality of coils of said actuators are coupled to a common reference of said converter, the cylinder valves in an internal combustion engine, the converter having a first and second capacitors and a voltage source, the converter actuated via at least two switches per coil to energize coils in said actuator; and 
 a controller to activate each of said switches to route electrical energy from at least one of said capacitors through each of said plurality of coils in any one of two opposing directions. 
 
     
     
       11. The system of  claim 10  wherein said bi-directional converter maintains a charge balance on said first and second capacitors. 
     
     
       12. The system of  claim 11  wherein said converter is adapted to be coupled to a plurality of engine cylinder valves. 
     
     
       13. The system of  claim 12  wherein said bi-directional converter maintains a charge balance on said first and second capacitors even when at least one cylinder of the engine is deactivated while at least one other cylinder carries out combustion. 
     
     
       14. The system of  claim 11  wherein said capacitors form a dual voltage source. 
     
     
       15. The system of  claim 11  wherein said bi-directional converter is adapted to be coupled to at least two dual coil actuators of two cylinder valves, wherein the converter is configured to balance voltage of said first and second capacitors. 
     
     
       16. A system, comprising:
 a bi-directional converter adapted to be coupled to a plurality of single or multiple coil actuators having a permanent magnet, said actuators coupled to valves of a cylinder, where a plurality of coils of said actuators are coupled to a common reference of said converter, the cylinder valves in an internal combustion engine, the converter having first and second energy storage devices and a voltage source, the converter actuated via at least two switches per coil to energize coils in said actuator; 
 a controller to activate each of said switches to route electrical energy from each of said energy storage devices through each of said plurality of coils in any one of two opposing directions. 
 
     
     
       17. The system of  claim 16  wherein said controller further selectively activates said switches to maintain a charge level of said capacitors.